1. Field of the Invention
The invention relates generally to light-emitting diode (LED) lighting, and more particularly to joint support and strain relief for connecting LED strip light to a cable.
2. Description of Related Art
Over the last decade, light-emitting diode (LED)-based lighting has become popular in both residential and commercial lighting applications because of its efficiency, adaptability, and its wide range of color and color temperature options. One of the most popular forms of LED light is the strip light—a long, flexible printed circuit board (PCB) with LED light engines connected to the PCB at a regular interval along its length. Strip light can be placed in long extrusions, which are typically covered by diffusers, to provide the same sort of form factor and light quality that a traditional fluorescent or incandescent fixture might, and it has a plethora of other uses. Backed by adhesive, strip light can adhere to essentially any surface, and is sometimes referred to as tape light. Depending on its type and operating voltage, a strip light may extend anywhere from a few meters to more than 50 meters.
U.S. Pat. No. 9,239,136 to Russell Petersen et al., the work of the present assignee and incorporated by reference in its entirety, illustrates and describes a typical configuration of strip light. As this patent bears out, one of the persistent challenges with strip light lies in connecting the strip light to power. The typical solution is simply to solder wires to the strip light. However, solder joints are fragile, and relying on a solder joint to provide both mechanical and electrical connection is inadvisable.
Moreover, while it might be easy to solder a connection in a factory, or in another controlled environment, power connections to strip light are often made either in the field by installers, typically electricians or laborers. Field installers often operate under time pressure with a limited toolset and in ambient conditions that may include dirt, dust, or other particulates that can foul a joint or connection. Making a proper, robust electrical and mechanical connection under these field conditions can be difficult, and if a connection is improper or fails, it can be equally difficult to trace the source of the failure during an installation.
In some cases, instead of soldering a wire directly, the wire may be connected to a terminal, such as a crimp terminal, and that terminal used to make any further electrical or mechanical connections. The Petersen patent, which was incorporated by reference above, shows one example of how terminals may be used in this context to make electrical and mechanical connections with individual wires. U.S. Pat. No. 8,951,063, which is incorporated by reference in its entirety, illustrates another example of a crimp terminal—in this case, a cuff that surrounds the end of the wire and makes electrical connection to it and a flat, annular connecting “spade” that extends outwardly and can be used to make further electromechanical connection.
While there are structures, like spade connectors, for connecting individual wires electrically and mechanically, there are relatively few solutions for providing mechanical support to an entire joint. One example of a mechanical joint support can be found in most consumer appliances: a molded plastic or rubber “strain relief” is often provided at the point where a power cable joins the element to which it is supplying power. The molded strain relief prevents the cable from bending too much at the point of connection and breaking off. However, this type of strain relief is typically an integral part of the cord, installed at manufacture, and it typically attaches a flexible cord to a rigid housing, rather than a flexible cord to a flexible PCB.